Fluid pump



A. F. LEIS FLUID PUMP Aug. 21, 1951 2 SheetsSheet 1 Filed July 15, 1947 Ill 1h Ill INVENTOR. ARTHUR F. LEIS ATTORNEYS.

7 Aug. 21, 1951 A. F. LEIS I 2,564,808

FLUID PUMP Filed July 15, 1947 2 Sheets-Sheet 2 INVENTOR. ARTH UR F'; LEiS ATTO RNEYS Patented Aug. 21, 1951 UNITED STATES PATENT OFFICE Claims. (Cl. 103161) This invention relates to fluid pumps. One of the objects of this invention is to provide a fluid pump having a plurality of arcuately shaped segments adapted to be driven in an eccentric path relative to the wall of the cylinder in such manner as to produce a pumping action.

Another object of the invention is to provide a fluid pump in which the rotor of the pump rotates within and is journalled in the cylinder of the pump, and in which a plurality of arcu ately shaped segments are positioned within the rotor and driven thereby in an eccentric path in relation to the cylinder to produce a pumping action.

It is also an object to provide a fluid pump of the character described in which the pumping action is obtained from a plurality of arcuately shaped segments carried by a rotor and driven thereby in an eccentric path relative to the pump cylinder, such segments extending beyond the ends of the rotor to engage with means to retain the segments in a pumping relationship relativ to the cylinder.

Another object is to provide an improved and simplified form of vane pump wherein the pumping action is obtained by changing the volume of chambers provided in the rotor of the pump by reciprocation of pumping segments therein upon rotation of the rotor.

An additional object is to provide a fluid pump in which the pumping segments carried and driven by the rotor are retained in engagement with an eccentric track, a means being provided to positively hold the segments in engagement with the eccentric track.

Another object is to provide a fluid pump having vanes cooperating with a sealing surface between the high and low pressure sides of the pump and adapted to displace all of the fluid from the pumping chambers on the high pressure side of the pump before passing over the sealing surface which eliminates any compression of fluid when the vane passes over the sealing surface.

A further object is to provide a pump of the character described adapted to produce high liquid pressures, and which expels the liquid from the pumping chambers as the vane passes over the sealing surface to prevent hydraulic knock caused by compression of liquid Within a locked or closed chamber.

Another object is to provide a fluid pump in accordance with the foregoing objects wherein the sealing surface between the high and low pressure sides of the pump is substantially less than the Width of the vane that cooperates there- 2 with, and on which the vane rolls from one edge to the other to discharge completely the high pressure fluid from the pumping chamber in which the vane is located as the vane passes across the sealing surface, to prevent the trapping of fluid between the vane and the sealing surface as the vane passes across.

It is another object to provide a fluid pump of the character described wherein the sealing surface between the high and low pressure sides of the pump on the intake side is at least equal to and preferably slightly greater than the width of a vane cooperating therewith to provide a seal between the intake and dischargeside of the pump, and in which the sealing surface between the high and low pressure sides of the pump on the discharge side thereof is less than one half the width of the vane cooperating therewith to provide against trapping a fluid between the vane and the sealing surface.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred form of embodiment of the invention is illustrated.

In the drawings:

Fig. 1 is a transverse cross-sectional view of the pump taken along line l-l of Fig. 2;

' Fig. 2 is a substantially vertical cross-sectional view of the pump taken along line 22 of Fig. 1;

Fig. 3 is a transverse cross-sectional view through the pump substantially along line 33 of Fig. 2 illustrating the track means for guiding the pumping segments;

Fig. 4 is an end elevational view of one of the pumping segments; and

Figs. 5, 6 and '7 are enlarged partial crosssectional views of the pump illustrating the action nected into the same for conducting fluid to and from the pump.

The fluid flow passages l2 and [3 are disposed on diametrically opposite sides of the pump and are associated with the recessed areas l6 and H, respectively. The recessed areas l6 and I1 provide chambers from which fluid is drawn by the pumping mechanism and into which fluid under 3 pressure is discharged depending upon the direction of rotation of the pump. Either of the chambers IE or I! may be the suction or the discharge chamber.

A rotor 20 is positioned within the cylinder bore II and rotates therein when driven by a shaft 2| that is integral with the rotor 20 and extends from the casing ID. The rotor 20 consists of a plurality of radially disposed arms 22 that extend longitudinally parallel with the axis of the rotor thereby forming chambers 23 therebetween in which pumping segments, members or vanes 24 are adapted to operate. The arms 22 are each provided with an enlarged head portion 25 that is provided with an arcuate surface 26 of substantially the same radial dimension as the radial dimension of the cylinder bore so that the periphery of the rotor 2c engages the cylinder bore II and the rotor thereby is journaled within the cylinder bore II for concentric rotation therewith.

Each of the chambers 23 provided between the arms 22 of the rotor has parallel side walls or surfaces 2! that are engaged by the pumping member 24 and which cooperates therewith to forma pumping chamber 23. The pumping segments or members 24 extend beyond the end walls 29 of the rotor, as illustrated in Fig. 2.

The recessed area I6 has a wall 50 that has the upper end thereof in spaced relationship to the upper end 52 of the wall 53 of the recessed area l1. Thespaced relationship between the ends 5| and 52 of the walls 50 and 53 is such that the sealing surface between these ends of the walls is slightly greater than the distance between the parallel walls21 of the rotor 20. Thus, when one of the vanes 24 is opposite the sealing surface or land 55, the end edges of adjacent segments 56 of the rotor 20 will engage the land 55 to thereby prevent connection between the high and low pressure sides of the pump represented by the chambers l6 and H, respectively. I

End caps 30 and 3| are secured to opposite ends of the casing by means of rods 32 that 1 extend through the end caps 30 and,3| and the casing ID, the rods 32 having nuts 33 threaded upon the ends thereof for this purpose. The end caps '30. and 3| each have recesses .or chambers 34 and 35, respectively, that are positioned I eccentrically relative to the cylinder bore I when the end caps are in position on the casing In. The recesses or chambers 34 and 35receive the ends of the pumpingmembers 24, the pumping members 24 being positioned in engagement with the side walls of the recesses to thereby regulate the radial position of the pumping members 24 relative to the axis of rotation of the rotor 20, and engage the bottom walls of the recesses 34 and 35 to locate the pumping members endwise in the rotor 20. a

' A circular disc 36 is positioned between the end cap 30 and the rotor 20, and is of such diameter as to engage the inner surfaces of the pumping members 24 to thereby retain them in engagement with the side wall of the recess 34 A circular ring 31 is provided between the end cap 3| and the rotor for this same purpose at the opposite end of the pumping members 24, the drive shaft 2| extending through the central opening 38 of the ring 31 and through a bearing 39 provided in the end cap 3| for the same.

As illustrated in Fig. 4, the pumping members 24 are initially cut from a circular ring 4,6 so

that each of the pumping members 24 is an arcuate segment, whereby the inner arcuate surface 4| of the pumping members 24 engage the peripheral surface of the disc 36 and the ring 31 while the outer arcuate surface 42 of the pumping members 24 engage the side walls of the recesses 34 and 35. As illustrated in Fig. 3, the cooperation of the recess 34 and the disc 36 provides an eccentric track 43 that is eccentrically positioned relative to the cylinder bore The recesses 34 and in the end caps 30 and 3| respectively are positioned eccentrically relative to the cylinder bore I so that the periphery of the recesses 34 and 35 is tangent with the periphery of the cylinder bore longitudinally along the land 60, midway between the edges thereof. Thus, as the vanes 24 are carried around the track formed by the recesses 34 and 35 and the circular disc 36 and the ring 31, the pumping segments or vanes 24 establish a line contact with the land between the ends 6| and 62 of the chamber recesses l6 and I1. The'action produced upon thepumping segments or vanes 24 by the rotor 20 is illustrated in Figs. 5 to '7 inclusive. In Fig. 5 a pumping segment or vane 24 is illustrated approaching the land 60, the leading edge of thepumping segment 24 being closerv to the periphery of the cylinder bore than the trailing edge 66. Thus, when the leading edge 65 of thepumping segment '24 enters-into cooperation withthe land 60, as illustrated in Fig. 6, the outer surface 61 of the pumping segmentor-vane '24 engages the land 60 to form a-fluidseal therewith to prevent passage of fluid. under pressure from chamber |1 into chamber l6. This seal is established before the element 56 of the rotor 20 leaves the land 60, as seen in Fig. 6.

It will be particularly noted in Figs. 5, 6, and 7 that the land 60 is relatively narrow in width, and is actually of lesser width than the element 56 of the rotor or of the vane 24. However, since line contact is formed between the vane 24 and the land 60, the vane 24 will seal between the chambers l6 and I! before the element 56 passes over the land 60.

Asthe rotor 20 continues clockwise movement of the vane 24, the line contact between the vane 24 and the land 60 continuously changes across the surface 61 of the vane 24 from the leading edge 65 thereof to the trailing edge 65, and as illustrated in Fig. '7, the line contact is now established,substantially midway between theleading and trailing edges of the vane 24. The trailing edge 66 of .the vane 24 thus continuously vmoves toward the cylinder bore H as it approaches the land 60, and by the time the trailing edge 66 passes over the edge 62 ofthe land 60, all fluid in the pumping chamber formed between the parallel walls of adjacent segments 56 of the rotor is discharged into the high, pressure chamber I! of the pump. The pumping segment or vane 24 thus sweeps the pumping chamber between the segments 56 of the rotor 20, clean of fluid under pressure before the leading edge I0 of the next segment 56 of the rotor, see Fig. '7, enters into cooperation with the land 6|].

Theoretically, the land 60 could be reduced in length until there was just slightly greater than a line contact between the land and the pumping segments because immediately upon the trailing edge of the pumping segments leaving the point A, the leading edge of the next segment 56 of. the rotore sases e point. A. In the preferred construction the land area surface 60 has a Width not greater than one-half thetransverse width of the segments or vanes 24.

From the foregoing description, it will be ap-,- parent that the construction of the pump provides for a narrow land area between the pumping segments and the land to allow the pumping segments to discharge all fluid from the pumping chambers before passing over the land, and thereby eliminate hydraulic knock in the case of liquid pumps, and eliminate a high compr sion of gas in the case of gas pumps.

It will now be apparent that when the rotor 20 is rotatably driven by the shaft 2|, in either direction, the pumping segments 24 will be driven around the eccentric track 43 and will simultaneously reciprocate within the pumping chambers 28 to change the volume thereof within the rotor 20 for drawing in fluid from one of the fluid conduits and discharging the same through the opposite conduit. Since the pumping members are each shaped as an arcuate segment, the bearing surfaces 4! and 42 thereof that engage the recesses 34 and 35 and the cooperating disc 36 and the ring 31 provide relatively long bearing surfaces that will permit a relatively long period of operation of the pump Without substantial wear to the bearing surfaces. I

As will be noted in Fig. 4 the edge walls 44 of the pumping segments 24 are each arcuately shaped as struck on an are from a center point substantially midway between the edges of the segment 24. These edge surfaces 44 engage the parallel surfaces 21 in the rotor 20. When the pumping segments are driven around the eccentric track 43 by the rotor 20 it will be apparent that the angular relationship between the parallel surfaces 21 and the edge surfaces 44' of the segments 24 will continuously change in positions during such rotation. Therefore, it becomes essential to provide a line contact between the segments 24 and the surfaces 27 of the rotor. However, since the force applied upon the segment developed as a result of compressing fluid is applied radially toward the axis of the rotor,

the long bearing surfaces at the ends of the pumping segments absorb the major friction as caused by the pumping action. The line contact surfaces, between the pumping members 24 and the surfaces 2! in the rotor, can thus be relied upon principally as sealing surfaces that will not have any substantial degree of frictional wear, because there is no large thrusts developed in the pump that are directednormal to the parallel surfaces 27 that need be carried by the pumping members 2 The only thrust in this direction is that developed by the driving action of the rotor upon the pumping members 24. However, since the driving angle between the surfaces 2'! of the rotor and the pumping members 24 is a relatively acute angle, this driving thrust will not be great and the frictional resistance of the pumping members can be easily overcome. It is, therefore, seen that the construction of this pump is such that there is a minimum amount of frictional wear upon the moving members of the pump and that Wherever the major frictional resistance occurs there are broad bearing surfaces to carry the same. This is particularly true of the vanes, orpumping members, that have caused particular trouble in vane pumps of prior construction wherein the narrow ends of the vanes were required to carry a major frictional load as caused by centrifugal action upon the vanes or by the necessity of 6 providing pressure beneath the vanes to hold them into engagement with the wall of the cylinder.

In order to prevent any internal pumping action between the rotor and the pumping members 24, the arms 22 of the rotor are each provided with a passage 46 that interconnect all of the chambers 23 whereby there is a free interflow of fluid between these chambers 23.

This application is a continuation-in-part of my co-pending application, Serial No. 509,174 filed November 6, 1943, now abandoned.

While the form of embodiment of the present invention as herein disclosed constitutes a preferred form, it is to be understood that other forms can be adopted, all coming within the scope of the appended claims.

I claim:

1. A, fluid pump comprising, a pump casing having a cylinder bore therein and fluid flow passages for conducting fluid to and away from said cylinder bore, a rotor journaled concentrically in said cylinder bore and having a plurality of longitudinally arranged chambers extending inwardly from the periphery thereof, a pumping. segment positioned in each of said chambers for radial reciprocation therein relative to said rotor and having an outer arcuate periphery transversely of the axis of the segment which cooperates with the outer arcuate periphery of the other segments in the rotor to form in cross-section arcs of a circle of lesser diameter than the diameter of said cylinder bore, annular track means operably engaged by said pumping segments and disposed adjacent opposite ends of said rotor eccentrically relative to said cylinder bore to provide radial reciprocation of said pumping segments upon rotation of said rotor, said track means being so positioned relative to said cylinder bore that said circle of which said segment surfaces form arcs is tan gentwith the periphery of said cylinder bore at one point, and a land area surface at said point cooperating with said segments to provide a substantially line contact seal between the high and low pressure sides of said pump, there being an oppositely disposed land area surface also providedto complete the fluid seal between the high and low pressure sides of the pump.

2. A fluid pump that includes, a pump casing having a cylinder bore therein and fluid flow passages for conducting fluid to and away from said cylinder bore, a rotor journaled concentrically in said cylinder bore and having a plurality of longitudinally arranged chambers extending inwardly from the periphery thereof, a pumping segment positioned ineach of said chambers for radial reciprocation therein relative to said rotor and having an outer arcuate periphery transversely of the aXis of the segment which cooperates with the outer arcuate periphery of the other segments in the rotor to form in crosssection arcs of a circle of lesser diameter than the diameter of said cylinder bore, annular track means operably engaged by said pumping segments and disposed adjacent opposite ends of said' rotor eccentrically relative to said cylinder bore whereby to cause radial reciprocation of said pumping segments upon rotation of said rotor, said track means being so positioned relative to said cylinder bore that said circle of which said segment surfaces form arcs is tangent with the periphery of said cylinder bore at one point, and a land area surface at said point having a width substantially less than the transverse width of said segments cooperating therewith to form a fluidfseal between the high and low pressure sides of the pump and establishing a Substantially line contact with said segments to prevent trapping of fluid between said land area and said segments during passage of the segments over the land area, there being an oppositely disposed'sealing surface provided to complete the fluid seal between the high and low pressure sides of the pump having a transverse dimension at least equal to the transverse dimension of said pumping segments.

3. A fluid pump that includes, a pump casing having a cylinder bore therein and fluid flow passages for conducting fluid to and away from said cylinder bore, a rotor positioned in said cylinder bore and having a plurality of longitudinally arranged chambers extending inwardly from the periphery thereof separated by rotor segments arranged longitudinally thereof for journaling said rotor in said cylinder bore, a pumping segment or vane positioned in each of said chambers for radial reciprocation therein relative to said rotor and having an outer arcuate periphery transversely of the axis of the segment which cooperates with the outer arcuate peripheries of the other segments in the rotor to form in crosssection arcs of a circle of lesser diameter than the diameter of said cylinder bore, sealing surface means coextensive with the diameter of said cylinder bore positioned on opposite sides of said rotor and engaged by said rotor segments to provide a fluid seal therebetween during rotation of the rotor, and circular track means of a diameter less than the diameter of said cylinder bore engaged by the outer peripheries of said pumping segments to control the radial reciprocation thereof in said chambers in said rotor and positioned eccentrically relative to said rotor such that the periphery of said track is tangent with the periphery of said cylinder bore at a point within the area of one of said seal surfaces to thereby cause said pumping segments to engage the seal surface in a substantially line contact at the said point continuously from the leading longitudinal edge to the trailing longitudinal edge as the pumping segments sweep across the said surface, the said sealing surface having a transverse dimension not greater than one-half the transverse dimension of said pumping segments whereby the trailing edge of each of the pumping segments expels all fluid from the rotor chamber in which it slides as it passes across the said sealing surface before the rotor segment that follows the said pumping segment engages the said sealing surface.

4. A fluid pump that includes, a pump casing I" having a cylinder bore therein and fluid flow passages for conducting fluid to and away from said cylinder bore, a rotor positioned in said cylinder bore and having a plurality of longitudinallyarranged chambers extending inwardly from the periphery thereof separated by rotor segments by which said rotor is journaled in said cylinder bore, sealing surfaces coextensive with said cylinder bore on opposite sides thereof engaged by said rotor segments for sealing between the high and low pressure sides of the pump, a transversely arcuately shaped pumping segment positioned in each of said chambers for radial reciprocation therein which cooperate to form in cross-section arcs of a circle of lesser diameter than the diameter of said sealing bore, and annular track means positioned adjacent each end of said rotor engaged by the ends of said pumping segments and positioned eccentrically relative to said cylinder bore to position the periphery thereof tangentially with the periphery of said cylinder bore at one point within the area of one of said sealing surfaces whereby to cause the outer peripheries of each of said pumping segments to establish a line contact with the said one sealing surface, which line contact changes its location continuously transversely across the said pumping segment from the leading longitudinal edge to the trailing longitudinal edge upon movement of the said pumping segment across the said one surface, the said sealing surface having a transverse dimension not greater than one-half the transverse dimension of a pumping segment whereby the trailing edge of each of the pumping segments expels all fluid from the rotor chamber, in which it slides, as it passes across the said sealing surface before the rotor segment, that follows the said pumping segment, engages the said sealing surface.

5 A fluid pump that includes, a pump casing having a cylinder bore therein and fluid flow pas sages for conducting fluid to and away from said cylinder bore, a rotor positioned in said cylinder bore and having a plurality of longitudinally arranged chambers extending inwardly from the periphery thereof and separated by rotor segments arranged longitudinally thereof for journaling said rotor in said cylinder bore, a pumping segment positioned in each of said chambers for radial reciprocation therein relative to saidrotor and having an outer arcuate periphery transversely of the axis of the segment which cooperates with the outer arcuate peripheries of the other segments in the rotor to form in cross-section arcs of a circle of lesser diameter than the diameter of said cylinder bore, sealing surface means coextensive with the diameter of said cylinder bore positioned on opposite sides of said rotor and engaged by said rotor segments to provide a fluid seal therebetween during rotation of the rotor, and circular track means of a diameter less than the diameter of said cylinder bore engaged by the outer peripheries of said pumping segments to control the radial reciprocation thereof in said chambers in said rotor and positioned eccentrically relative to said rotor such that the periphery of said track is tangent with the periphery of said cylinder bore at a point within the area of one of said sealing surfaces to thereby cause each of said pumping segments to engage the sealing surface in a substantially line contact at the said point continuously from the leading longitudinal edge to the trailing longitudinal edge as the pumping segment sweeps across the said surface, the said one sealing surface having a transverse dimension not greater than one-half the transverse dimension of a pumping segment whereby the trailing edge of each of the pumping segments expels all fluid from the rotor chamber in which it slides as it passes across the said sealing surface before the rotor segment, that follows the said pumping segment, engages the said sealing surface, the other of said sealing surfaces having a transverse dimension at least equal to the transverse dimension of a pumping segment to thereby provide a seal between adjacent rotor segments.

6. A fluid pump that includes a pump casing having a cylinder bore therein and fluid flow passages for conducting fluid to and away from saidcylinder bore, a rotor in said cylinder bore journaled concentrically therewith and having a plurality of chambers therein extending inwardly from the periphery of the rotor and longitudinally of the axis thereof, each chamber having parallel walls, a pumping segment slidably fitting between the walls in each of said chambers to change the volume thereof and thereby produce a pumping action, said segments each having a surface transversely of the axis thereof that is an arc of a circle of lesser diameter than the diameter of said cylinder bore, and track means disposed adjacent each end of said rotor eccentrically thereto and engaged by said pumping segments so that said surfaces are tangent with the periphery of said cylinder bore at one point upon rotation of said rotor which causes reciprocation of said segments in said chambers.

7. A fluid pump that includes, a pump casing having a cylinder bore therein and fluid flow passages for conducting fluid to and away from said cylinder bore, a rotor journaled in said cylinder bore and having a plurality of chambers therein extending inwardly from the periphery of the rotor and longitudinally of the axis thereof, the rotor surfaces forming each chamber being parallel, a pumping segment slidably fitting between said parallel walls in each of said chambers to change the volume thereof and thereby produce a pumping action, said segments each having a surface transversely of the axis thereof is that is an arc of a circle of lesser diameter than the diameter of said cylinder bore, end walls for closing the ends of said cylinder bore, and track means in said end walls positioned eccentrically relative to the axis of said rotor and engaged by i said pumping segments so that said surfaces are tangent with the periphery of said cylinder bore at one point upon rotation of said rotor which causes reciprocation of said segments in said chambers.

8. A fluid pump that includes a pump casing having a cylinder bore therein and fluid flow passages for conducting fluid to and away from said cylinder bore, a rotor in said cylinder bore journaled concentrically therewith and having means forming a plurality of chambers therein, the walls of each chamber being parallel, a pumping segment slidably fitting between the parallel walls in each of said chambers, said segments each having a surface transversely of the axis thereof that is an arc of a circle of lesser diameter than the diameter of said cylinder bore, end walls for closing the ends of said cylinder bore, each wall having a recess forming an endless track, each track being positioned eccentrically relative to said rotor, each of said pumping segments having its exterior surfaces guided by said tracks into tangency with the periphery of said cylinder bore at one point upon rotation of said rotor, and means disposed within said recess means in engagement with the interior end surfaces of said pumping segments to retain the same in engagement with said tracks.

9. A fluid pump that includes, a pump casing having a cylinder bore therein, fluid flow passages for conducting fluid to and away from said cylinder bore, a rotor journaled in said cylinder bore and journaled concentrically thereof and engaging said cylinder bore and having a plurality of chambers therein extending inwardly from the periphery of the rotor and longitudinally of the axis thereof, an arcuately shaped pumping segment having a transverse cross-section of an arc of a circle of less diameter than the diameter of said cylinder bore disposed in each of said chambers for radial reciprocation therein relative to the axis of said rotor, and a circular track means adjacent each end of said rotor positioned eccentrically relative thereto and engaged by said pumping segments so that the outer surfaces of said segments engage at one point with the periphery of said cylinder bore in line contact therewith upon rotation of said rotor which cause radial reciprocation of said pumping segments.

10. A fluid pump that includes, a pump casing having a cylinder bore therein and fluid flow passages for conducting fluid to and away from said cylinder bore, a rotor in said cylinder bore and journaled concentrically therewith and engaging said cylinder bore and having a plurality of circumferentially spaced chambers therein each chamber having parallel walls, an arcuately shaped pumping segment having a transverse cross-section of an arc of a circle of less diameter than the diameter of said cylinder bore slidably fitting between the walls in each of said chambers for radial reciprocation therein relative to said rotor, end walls for closing the ends of said cylinder bore having a circular recess therein of less diameter than the diameter of said cylinder bore positioned eccentrically relative to said rotor and having the outermost surface thereof tangent with said cylinder bore at one point, said arouately shaped pumping segments extending beyond the ends of said rotor into said recess for engaging the outer wall thereof, and means positioned within said recess and engaging the inner peripheral ends of said segments for retaining the same in engagement with walls of said recesses.

ARTHUR. F. LEIS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 838,458 Rogers Dec. 11, 1906 891,372 Reichhelm June 23, 1908 999,753 Curtis Aug. 8, 1911 1,087,181 Pitman Feb. 17, 1914 2,233,534 Jaworowski Mar. 4, 1941 

